First, the regulation of temperature
1. Keep warm. 1 strengthen the insulation construction. The structure of the facility shall be in line with the design of thermal insulation, using a shed film with a small thermal conductivity, opaque covering materials (grass weeds, paper quilts, insulation, etc.) and building materials, digging the heat conduction in the cut-off area of ​​cold trenches, and building wind barriers, etc. Thick sunlight greenhouse wall and back slope, the ground covered with black plastic film. 2 multi-layer coverage. Multilayer coverage is very effective in reducing cross-flow heat release. Such as the temperature outside covered with straw and paper, double film cover, hanging insulation screen, indoor buckle small arch shed, etc., these measures can be used alone or in combination. 3 Master the time for uncovering the grass and paper. Accurately understanding the time of covering grass and quilts in winter can make the shed temperature rise 2°C to 3°C in a short time, and then decrease very slowly. If the temperature does not increase after the cover, but it keeps falling, it means that the cover is late. After removing the grass and paper, the temperature dropped by l°C to 2°C for a short period of time, and then recovered. If the room temperature is significantly higher than the critical temperature for the growth and development of the fruit tree before exposing it, it can be exposed early after sunrise. During production, exposing time can be determined according to the height of the sun. In general, when the sun covers the entire front slope, it can be lifted. Special weather is treated differently. In high winds or extreme cold weather, late departures should be covered as early as possible. Uncovering the grass on cloudy days is conducive to the use of scattered light, so that the indoor temperature rises.
2. Warm up. 1 heating wire heating: air heating and heating two forms. The electric heating wire is made of 0.6 mm No. 70 carbon alloy steel wire as a resistance wire, and is coated with a heat-resistant vinyl resin as an insulating layer. When it is necessary to increase the temperature, the electric heating wire is set up in the indoor space and the electricity can be supplied. Due to the large power consumption, it is generally only suitable for temporary heating. Warming stove (warming room) Warming: Increase the air temperature inside the shed by sending warmed air. There are two types of heating methods: upper blowing and lower blowing. The upper blow-out hot blast stove blows hot air from the upper part of the hot air blower. The air temperature in the shed is evenly distributed, but the vertical gradient is large, the upper temperature is high, the lower temperature is low, and the heat loss is large. In the lower blow-out hot-blast stove, hot air is blown out from the lower part of the hot air blower. The vertical distribution of air temperature in the shed is uniform and unevenly distributed horizontally. The hot air stove should pay attention to matters: hot blast stove must be located in the shed; should be used in conjunction with multi-layered cover to reduce the waste of heat; outlet temperature should not be too high; plastic ventilation tube cooling holes do not directly align with the tree. According to the growth and development of the cherry, it is appropriate to determine whether or not the temperature will be warmer. At night, the air supply starts at 21 o'clock, and it ignites about 1 hour before the air supply. 2 Fire heating: It is the most frequently used temperature-increasing measure in the greenhouse. Sunlight greenhouses and plastic greenhouses need to be heated by iron stoves in case of temporary warming in the case of falling snow in the early spring. The chimneys can be set up or not. When permanent heating is required, there are many self-made stoves. Generally, there is a stove every 3 to 4 inside the northern wall of the greenhouse. It consists of a pit, a furnace, a coal inlet, a fire outlet, and a flue, and it depends on the burner when burning coal. And flue cooling. The use of furnace heating should pay attention to the safety of the operator, proper ventilation, a time can not be too long to prevent the occurrence of carbon monoxide or sulfur dioxide poisoning. 3 Burning and warming: In warmer areas, it can be temporarily warmed by combusting biogas, alcohol, diesel, charcoal, etc. when cold currents cause strong cooling. The effect is quite good. Combustion and heating cannot burn firewood or coal in the shed. If charcoal combustion is used for heating, attention should be paid to the hazards of toxic gases such as carbon monoxide. 4 Heated water heating: The water is fed into the boiler to warm up, and the water is turned into steam, hot water or warm water. It is introduced into the iron pipe or radiator in the protection facility through the transfer iron pipe to increase the temperature; after cooling, it is returned from the return pipe. The boiler is reheated and continuously circulated. If there is waste heat from the power plant and other factories, the pipes can be buried in the input room so that the hot water or hot gas can circulate in the pipe to increase the temperature. 5 hot water bottle heating. During the day, water bags are placed in large greenhouses. The water has a large specific heat, and it absorbs sunlight energy during the day and converts it into heat energy. It gradually releases heat energy when it cools at night, thereby increasing the temperature of the greenhouse.
3. Cool down. 1 cover shading. The use of shading measures such as cover plates reduces the amount of solar radiation entering the booth. Less use due to reduced light. 2 ventilation cooling. Ventilation should be flexible according to the season and weather conditions. In winter and early spring, ventilation is generally performed at noon with high ambient temperatures, and the size of the air outlet and the length of ventilation time must be controlled so that the temperature does not drop sharply. In addition, attention should also be paid to the direction in which the air outlet is opened, and the air should be released from the leeward position so as not to infiltrate a large amount of cold air. 3 evaporation heat. When the relative humidity of the air is low, ground irrigation or water spraying is performed. The evaporation of moisture consumes a large amount of heat energy, thereby lowering the air temperature.
Second, the regulation of ground temperature
After the temperature in the shed cherry shed was warmed up, the ground temperature rose slowly, and the shed temperature rose rapidly. The two did not coordinate with each other, often resulting in slow germination, prolonged flowering, and even the phenomenon of “flowering after the first leavesâ€. In addition, the surface temperature of the soil in which the roots of cherry trees are concentrated is greatly changed in one day, which seriously affects the absorption function and growth of the root system. In the 20 to 30 days before the baiting, after fully irrigating, the surface coating can make the ground temperature rise slowly in advance; when the shed is warmed, the ground temperature and the shed temperature can be coordinated, which is beneficial to the growth and development of fruit trees. In principle, it is advocated to cover the mulching film as early as possible, and when it is near to the shed, the temperature rise effect will be poor, and even the temperature will rise even more slowly.
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